Straw person fallacy
According to Discovering the World through Debate, a straw person fallacy "Occurswhen an arguer, intentionally or unintentionally, misinterprets an opponent's argument, then proceeds to refute the misinterpreted argument as if it were the opponent's actual argument" (250).
Trapp, Robert, et al. Discovering the World through Debate: A Practical Guide to Educational Debate for Debaters, Coaches, and Judges. Third Edition. New York: IDEA Press Books, 2005.